
export default class Noise {

    private static grad3 = [[1, 1, 0], [-1, 1, 0], [1, -1, 0], [-1, -1, 0],
    [1, 0, 1], [-1, 0, 1], [1, 0, -1], [-1, 0, -1],
    [0, 1, 1], [0, -1, 1], [0, 1, -1], [0, -1, -1]];

    private static perm = [];

    private static dot2(g: number[], x: number, y: number) {
        return g[0] * x + g[1] * y;
    }

    private static dot3(g: number[], x: number, y: number, z: number) {
        return g[0] * x + g[1] * y + g[2] * z;
    }

    private static mix(a: number, b: number, t: number) {
        return (1.0 - t) * a + t * b;
    }

    private static fade(t: number) {
        return t * t * t * (t * (t * 6.0 - 15.0) + 10.0);
    }

    public static snoise(x: number, y: number) {
        var n0, n1, n2; // Noise contributions from the three corners 
        // Skew the input space to determine which simplex cell we're in 
        var F2 = 0.5 * (Math.sqrt(3.0) - 1.0);
        var s = (x + y) * F2; // Hairy factor for 2D 
        var i = Math.floor(x + s);
        var j = Math.floor(y + s);
        var G2 = (3.0 - Math.sqrt(3.0)) / 6.0;
        var t = (i + j) * G2;
        var X0 = i - t; // Unskew the cell origin back to (x,y) space 
        var Y0 = j - t;
        var x0 = x - X0; // The x,y distances from the cell origin 
        var y0 = y - Y0;
        // For the 2D case, the simplex shape is an equilateral triangle. 
        // Determine which simplex we are in. 
        var i1, j1; // Offsets for second (middle) corner of simplex in (i,j) coords 
        if (x0 > y0) { i1 = 1; j1 = 0; } // lower triangle, XY order: (0,0)->(1,0)->(1,1) 
        else { i1 = 0; j1 = 1; }      // upper triangle, YX order: (0,0)->(0,1)->(1,1) 
        // A step of (1,0) in (i,j) means a step of (1-c,-c) in (x,y), and 
        // a step of (0,1) in (i,j) means a step of (-c,1-c) in (x,y), where 
        // c = (3-sqrt(3))/6 
        var x1 = x0 - i1 + G2; // Offsets for middle corner in (x,y) unskewed coords 
        var y1 = y0 - j1 + G2;
        var x2 = x0 - 1.0 + 2.0 * G2; // Offsets for last corner in (x,y) unskewed coords 
        var y2 = y0 - 1.0 + 2.0 * G2;
        // Work out the hashed gradient indices of the three simplex corners 
        var ii = i & 255;
        var jj = j & 255;
        var gi0 = this.perm[ii + this.perm[jj]] % 12;
        var gi1 = this.perm[ii + i1 + this.perm[jj + j1]] % 12;
        var gi2 = this.perm[ii + 1 + this.perm[jj + 1]] % 12;
        // Calculate the contribution from the three corners 
        var t0 = 0.5 - x0 * x0 - y0 * y0;
        if (t0 < 0) n0 = 0.0;
        else {
            t0 *= t0;
            n0 = t0 * t0 * this.dot2(this.grad3[gi0], x0, y0);  // (x,y) of grad3 used for 2D gradient 
        }
        var t1 = 0.5 - x1 * x1 - y1 * y1;
        if (t1 < 0) n1 = 0.0;
        else {
            t1 *= t1;
            n1 = t1 * t1 * this.dot2(this.grad3[gi1], x1, y1);
        }
        var t2 = 0.5 - x2 * x2 - y2 * y2;
        if (t2 < 0) n2 = 0.0;
        else {
            t2 *= t2;
            n2 = t2 * t2 * this.dot2(this.grad3[gi2], x2, y2);
        }
        // Add contributions from each corner to get the final noise value. 
        // The result is scaled to return values in the interval [-1,1]. 
        return 70.0 * (n0 + n1 + n2);
    }

    public static snoise3(x: number, y: number, z: number) {
        var n0, n1, n2, n3; // Noise contributions from the four corners 
        // Skew the input space to determine which simplex cell we're in 
        var F3 = 1.0 / 3.0;
        var s = (x + y + z) * F3; // Very nice and simple skew factor for 3D 
        var i = Math.floor(x + s);
        var j = Math.floor(y + s);
        var k = Math.floor(z + s);
        var G3 = 1.0 / 6.0; // Very nice and simple unskew factor, too 
        var t = (i + j + k) * G3;
        var X0 = i - t; // Unskew the cell origin back to (x,y,z) space 
        var Y0 = j - t;
        var Z0 = k - t;
        var x0 = x - X0; // The x,y,z distances from the cell origin 
        var y0 = y - Y0;
        var z0 = z - Z0;
        // For the 3D case, the simplex shape is a slightly irregular tetrahedron. 
        // Determine which simplex we are in. 
        var i1, j1, k1; // Offsets for second corner of simplex in (i,j,k) coords 
        var i2, j2, k2; // Offsets for third corner of simplex in (i,j,k) coords 
        if (x0 >= y0) {
            if (y0 >= z0) { i1 = 1; j1 = 0; k1 = 0; i2 = 1; j2 = 1; k2 = 0; } // X Y Z order 
            else if (x0 >= z0) { i1 = 1; j1 = 0; k1 = 0; i2 = 1; j2 = 0; k2 = 1; } // X Z Y order 
            else { i1 = 0; j1 = 0; k1 = 1; i2 = 1; j2 = 0; k2 = 1; } // Z X Y order 
        }
        else { // x0<y0 
            if (y0 < z0) { i1 = 0; j1 = 0; k1 = 1; i2 = 0; j2 = 1; k2 = 1; } // Z Y X order 
            else if (x0 < z0) { i1 = 0; j1 = 1; k1 = 0; i2 = 0; j2 = 1; k2 = 1; } // Y Z X order 
            else { i1 = 0; j1 = 1; k1 = 0; i2 = 1; j2 = 1; k2 = 0; } // Y X Z order 
        }
        // A step of (1,0,0) in (i,j,k) means a step of (1-c,-c,-c) in (x,y,z), 
        // a step of (0,1,0) in (i,j,k) means a step of (-c,1-c,-c) in (x,y,z), and 
        // a step of (0,0,1) in (i,j,k) means a step of (-c,-c,1-c) in (x,y,z), where 
        // c = 1/6.
        var x1 = x0 - i1 + G3; // Offsets for second corner in (x,y,z) coords 
        var y1 = y0 - j1 + G3;
        var z1 = z0 - k1 + G3;
        var x2 = x0 - i2 + 2.0 * G3; // Offsets for third corner in (x,y,z) coords 
        var y2 = y0 - j2 + 2.0 * G3;
        var z2 = z0 - k2 + 2.0 * G3;
        var x3 = x0 - 1.0 + 3.0 * G3; // Offsets for last corner in (x,y,z) coords 
        var y3 = y0 - 1.0 + 3.0 * G3;
        var z3 = z0 - 1.0 + 3.0 * G3;
        // Work out the hashed gradient indices of the four simplex corners 
        var ii = i & 255;
        var jj = j & 255;
        var kk = k & 255;
        var gi0 = this.perm[ii + this.perm[jj + this.perm[kk]]] % 12;
        var gi1 = this.perm[ii + i1 + this.perm[jj + j1 + this.perm[kk + k1]]] % 12;
        var gi2 = this.perm[ii + i2 + this.perm[jj + j2 + this.perm[kk + k2]]] % 12;
        var gi3 = this.perm[ii + 1 + this.perm[jj + 1 + this.perm[kk + 1]]] % 12;
        // Calculate the contribution from the four corners 
        var t0 = 0.6 - x0 * x0 - y0 * y0 - z0 * z0;
        if (t0 < 0) n0 = 0.0;
        else {
            t0 *= t0;
            n0 = t0 * t0 * this.dot3(this.grad3[gi0], x0, y0, z0);
        }
        var t1 = 0.6 - x1 * x1 - y1 * y1 - z1 * z1;
        if (t1 < 0) n1 = 0.0;
        else {
            t1 *= t1;
            n1 = t1 * t1 * this.dot3(this.grad3[gi1], x1, y1, z1);
        }
        var t2 = 0.6 - x2 * x2 - y2 * y2 - z2 * z2;
        if (t2 < 0) n2 = 0.0;
        else {
            t2 *= t2;
            n2 = t2 * t2 * this.dot3(this.grad3[gi2], x2, y2, z2);
        }
        var t3 = 0.6 - x3 * x3 - y3 * y3 - z3 * z3;
        if (t3 < 0) n3 = 0.0;
        else {
            t3 *= t3;
            n3 = t3 * t3 * this.dot3(this.grad3[gi3], x3, y3, z3);
        }
        // Add contributions from each corner to get the final noise value. 
        // The result is scaled to stay just inside [-1,1] 
        return 32.0 * (n0 + n1 + n2 + n3);
    }

    public static cnoise3(x: number, y: number, z: number) {
        // Find unit grid cell containing point 
        var X = Math.floor(x);
        var Y = Math.floor(y);
        var Z = Math.floor(z);

        // Get relative xyz coordinates of point within that cell 
        x = x - X;
        y = y - Y;
        z = z - Z;

        // Wrap the integer cells at 255 (smaller integer period can be introduced here) 
        X = X & 255;
        Y = Y & 255;
        Z = Z & 255;

        // Calculate a set of eight hashed gradient indices 
        var gi000 = this.perm[X + this.perm[Y + this.perm[Z]]] % 12;
        var gi001 = this.perm[X + this.perm[Y + this.perm[Z + 1]]] % 12;
        var gi010 = this.perm[X + this.perm[Y + 1 + this.perm[Z]]] % 12;
        var gi011 = this.perm[X + this.perm[Y + 1 + this.perm[Z + 1]]] % 12;
        var gi100 = this.perm[X + 1 + this.perm[Y + this.perm[Z]]] % 12;
        var gi101 = this.perm[X + 1 + this.perm[Y + this.perm[Z + 1]]] % 12;
        var gi110 = this.perm[X + 1 + this.perm[Y + 1 + this.perm[Z]]] % 12;
        var gi111 = this.perm[X + 1 + this.perm[Y + 1 + this.perm[Z + 1]]] % 12;

        // Calculate noise contributions from each of the eight corners 
        var n000 = this.dot3(this.grad3[gi000], x, y, z);
        var n100 = this.dot3(this.grad3[gi100], x - 1, y, z);
        var n010 = this.dot3(this.grad3[gi010], x, y - 1, z);
        var n110 = this.dot3(this.grad3[gi110], x - 1, y - 1, z);
        var n001 = this.dot3(this.grad3[gi001], x, y, z - 1);
        var n101 = this.dot3(this.grad3[gi101], x - 1, y, z - 1);
        var n011 = this.dot3(this.grad3[gi011], x, y - 1, z - 1);
        var n111 = this.dot3(this.grad3[gi111], x - 1, y - 1, z - 1);
        // Compute the fade curve value for each of x, y, z 
        var u = this.fade(x);
        var v = this.fade(y);
        var w = this.fade(z);
        // Interpolate along x the contributions from each of the corners 
        var nx00 = this.mix(n000, n100, u);
        var nx01 = this.mix(n001, n101, u);
        var nx10 = this.mix(n010, n110, u);
        var nx11 = this.mix(n011, n111, u);
        // Interpolate the four results along y 
        var nxy0 = this.mix(nx00, nx10, v);
        var nxy1 = this.mix(nx01, nx11, v);
        // Interpolate the two last results along z 
        var nxyz = this.mix(nxy0, nxy1, w);

        return nxyz;
    }

}

function Alea(args?: any) {
    var s0 = 0;
    var s1 = 0;
    var s2 = 0;
    var c = 1;

    if (!args || args.length == 0) {
        args = [+new Date];
    }
    var mash = Mash();
    s0 = mash(' ');
    s1 = mash(' ');
    s2 = mash(' ');

    for (var i = 0; i < args.length; i++) {
        s0 -= mash(args[i]);
        if (s0 < 0) {
            s0 += 1;
        }
        s1 -= mash(args[i]);
        if (s1 < 0) {
            s1 += 1;
        }
        s2 -= mash(args[i]);
        if (s2 < 0) {
            s2 += 1;
        }
    }
    var random = function () {
        var t = 2091639 * s0 + c * 2.3283064365386963e-10; // 2^-32
        s0 = s1;
        s1 = s2;
        return s2 = t - (c = t | 0);
    };
    (random as any).uint32 = function () {
        return random() * 0x100000000; // 2^32
    };
    (random as any).fract53 = function () {
        return random() +
            (random() * 0x200000 | 0) * 1.1102230246251565e-16; // 2^-53
    };
    return random;
}

function Mash() {
    var n = 0xefc8249d;
    var mash = function (data: any) {
        data = data.toString();
        for (var i = 0; i < data.length; i++) {
            n += data.charCodeAt(i);
            var h = 0.02519603282416938 * n;
            n = h >>> 0;
            h -= n;
            h *= n;
            n = h >>> 0;
            h -= n;
            n += h * 0x100000000; // 2^32
        }
        return (n >>> 0) * 2.3283064365386963e-10; // 2^-32
    };
    return mash;
}

var random = Alea();
var p: number[] = [];
for (var i = 0; i < 256; i++) {
    p[i] = Math.floor(random() * 256);
}

for (var i = 0; i < 512; i++) {
    (Noise as any).perm[i] = p[i & 255];
}
